In the preceding project (R3) interarticulatory coordination patterns among the lips, jaw, larynx, and velopharyngeal mechanism during normal speech production were assessed. This project (R4) consists of studies of multi- articulator coordination in selected speech disorders in an attempt to gain additional perspectives about such coordinations. We propose to study speech disorders with a four different etiologies: apraxia of speech, speech of the prelingually deaf, speech of individuals with a repaired palatal cleft, and stutterers. We do not plan a traditional attempt to understand the etiological factors of each separate disorder. Instead, perspectives developed in the preceding project on speech production as a motor control system will be applied to breakdowns of the system. We want to understand the extent to which different articulator movement patterns within a disorder group may be associated with speech that is perceived as being normal versus abnormal. Movements of the lips, jaw, larynx, and velopharyngeal mechanism during a variety of speech and nonspeech tasks. The speech produced by speakers will be judged perceptually on a scale of "disordered". Based on analyses of movement and perceptual scaling data and, in particular, information gathered about articulator coordination characteristics or perceptually adequate versus inadequate speech produced by a given disorder group, we plan to extend these efforts to develop improved procedures for assessment of motor control in these populations, to develop more affective therapeutic approaches for speech improvement, and to assess the efficacy of such approaches.